From central to -- -- trial was the question of his affair with the murder victim's wife. Andrea -- -- and how much was real and how much -- Henne and mentioned. Did -- me tell you right away that he and having an affair with Andrea. Yes he would say I had an affair with her. Thank. He would say. We shared. The room and we had intimate relations. I think. But before he been brought into custody and decided to plead insanity. -- had been more clear. He said that quote she gave him. He never said we had sex all he said was that she gave him. And he said that it was great. Melanie white was the -- real -- and became a close friend of pennies. She says that for months before that claim that -- incident he had been calling her and obsessing over Andrea. I quit answering the phone I just. I was so tired of hearing him whine and -- He was like a school boy he was infatuated it was -- lovely -- And when this man -- need to entry into London. -- -- you heard all the details and they were laying on the bed together they watched -- -- they were groping and making out or whatever I -- -- He -- shouldn't became and I really don't want to hear about. But -- this infatuation. That he had with this woman and it over. He and Andrea -- -- -- The defense helped -- -- was relieved just help overcome Henne was. Arguing in essence that he was crazy in love. Making 10. The prosecution maintained that the affair proves just. -- -- was insane but crazy like a fox -- carefully plotted conspiracy. Both sides take the affair as a gift and even though and his -- he -- -- eight. Other witnesses confirm it. Nobody was in the bedroom nobody saw them having -- on when they were traveling on the road it's more. Totality of the circumstances you have witnesses who have no dog in this fight. Those said that -- southern groping and making out while it we don't know the extent of the physical nature of their relationship the sexual nature of their relationship. There was something inappropriate going on yes there's no doubt in your mine adultery was happening now. No doubt in my mind I don't have. And many following the trial wonder if an -- was the only thing -- was trying to hide me. There are also troubling questions about when she knew that her husband has been shocked she testified this -- -- predicted that an emergency. And rusty was taken to. Hospitals she raced over to the school without first doing what many think would have been natural. Many times did you call rest. Com rusty rusty zero to us. When you call us fish and they just something happens -- -- chances and he's answering his telephone they didn't tell you what. -- -- -- Did she look at it or seen T you. At all -- comfortable. To be on the stand she looked -- it was really incredible to see someone. Who showed me a grieving widow. Look aggravated. At -- -- becomes the trial of her husband's. Andrea testified she didn't know -- husband had been shot until she got to the hospital at about 11 AM. It took me into an eye contact Catherine. -- take a look at your chair. Someone I have no way do they are. Came home -- and -- he came in multiple gunshot wounds. And he was today. I don't remember anything he said yeah. Person you I don't think we'll -- you found out the hospital because you can show. That's -- okay. And then in the most heartbreaking testimony. That has been heard so far from Russell's father got on -- -- -- It's and said that Andrea called ten at about 9:36. In the morning and the words that he said. -- the courtroom. Here -- called us. And she called us. Rusty good -- -- so so sorry. And she was going to tell women proud to find out what happened and I'm sure that she told -- that rusty and -- cancer. There is no way to know what that explains what had happened harassed. Is it possible. That it. The -- -- -- heard Andrea. Well if you don't. Except that snyderman you know -- first ever had missed payments years -- their brain her former best friend. And a coworker corroborated the -- team that was a bombshell. That was Michelle that was the first time. People in the community. He really had something concrete around their head around Wednesday. Maybe she maybe she was -- on its. Speculation was further inflamed by the fact that Andrea snyderman stood to collect two million dollars from -- life insurance and some that might have been tempting to a financially strapped penny Newman. Do you think it -- Letterman had any plans to spend the rest of her life -- -- -- and. -- Two million dollars later she's free of her husband she's free of handing them to quote one of the lawyers and in this trial. They believe Andrea Snyder -- played -- -- like a -- yeah. -- regulated him into committing this murder yes when we come -- Both defense and the first. Turn the heat and not just don't know killer basin just Andrea might be a black widow. Not leaving much. -- -- -- --

This transcript has been automatically generated and may not be 100% accurate.

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